The Columbia SCOR in Arteriosclerosis comprises a multidisciplinary program of basic and clinical research directed at major questions in the areas of lipid metabolism, hyperlipidemia, atherosclerosis, thrombosis and coronary heart disease. A central focus is on the detailed study of patients with hyperlipidemia. The major projects under development consist of the following: (1) Metabolism of Cholesterol in Man. This project aims to examine in detail the turnover and metabolism of cholesterol in patients with hyperlipidemia. (2) Transport of Vitamin A in plasma. This project aims to examine the vitamin A transport system from chemical, physiological, and clinical points of view. (3) Platelet-Derived Growth Factor (PDGF). This project aims to study the regulation of the growth of arterial smooth muscle cells by factors released from platelets, and to isolate and characterize the PDGF. (4) Regional Myocardial Perfusion in Patients with Coronary Atherosclerosis. This project aims to develop and apply improved invasive and non-invasive radionuclide methods to measure regional myocardial perfusion in patients with coronary atherosclerosis and/or hyperlipidemia. (5) Intravascular Coaggulation and Thrombosis in Patients with Hyperlipidemia. This project aims to develop new methods to quantitate intravascular coagulation and platelet release in vivo, and to apply the methods to study patients with hyperlipidemia. (6) Metabolism of the Plasma Lipoproteins in Man. This project aims to study the metabolism of the plasma apolipoproteins in normal and in hyperlipidemic humans. (7) The Intestine and HDL Metabolism. This project aims to delineate the role of the intestine in the production and metabolism of HDL and in the regulation of plasma HDL levels.